JP2003277171A - METHOD FOR PRODUCING Si ALLOY-BASE COMPOSITE MATERIAL - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an Si alloy-base composite material improved in the brittleness of the conventional Si-base composite materials by infiltrating an Si alloy comprising Si and at least one metal into a molding, where the composite material can suppress the formation of a brittle carbide. <P>SOLUTION: A molding in which the amount of C is <1 mass% of the amount of SiC and an Si alloy comprising Si and at least one metal selected from the group comprising Al, Mg, Ni, Ti, Zr, Fe, Cr and Sn are put in a furnace and heated at 600-1,600°C and ≤5 Torr degree of vacuum to infiltrate the resulting molten alloy into the molding, thereby producing the objective Si alloy-base composite material. Thus, the brittleness of the conventional composite materials can be improved and manufacture of precision parts which require micromachining is facilitated. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a Si alloy-based composite material, and more particularly to a method for manufacturing a Si alloy-based composite material that is preferably used as a precision component that requires fine processing.

[0002]

2. Description of the Related Art A metal matrix composite material reinforced with ceramic particles or ceramic fibers has excellent characteristics as a ceramic such as high rigidity, low thermal expansion and wear resistance, and a metal having excellent ductility, high toughness and high thermal conductivity. It is known as a material having both excellent properties as

In particular, Si-based composite materials using SiC as a reinforcing material and Si as a metal are expected to be applied to the field of precision parts due to their excellent characteristics. Therefore, various methods have been proposed as the manufacturing method, but most of them are based on the manufacturing method in which molten Si is permeated into a molded body made of SiC and C.

[0004]

However, this Si-based composite material has a drawback that it is difficult to perform fine processing because both the constituent materials, SiC and Si, are brittle materials. International publication number W
As disclosed in Japanese Patent O 01/07377, a method for producing a composite material in which Si and a Si alloy composed of at least one metal are permeated has been proposed. However, in this method, the amount of C in the compact is 1 to 1 relative to SiC.
Since it is relatively large at 0% by mass, there is a problem that brittle carbides are formed by the reaction of C with a metal other than Si during penetration, and the obtained composite material becomes brittle. In particular, when Al is used as another metal, Al ₄ C ₃ is generated and reacts with water, which adversely affects the dimensional accuracy of the product.

The inventors of the present invention have conducted intensive research to solve the above problems and completed the invention. The purpose of the invention is to make Si and at least one kind of metal Si alloy permeate into a compact. It is an object of the present invention to provide a method for producing a Si alloy-based composite material, which can improve the brittleness of a conventional Si-based composite material and can suppress the formation of brittle carbide.

[0006]

SUMMARY OF THE INVENTION The above-mentioned object of the present invention is to provide a molded body molded using SiC and C with Si and A
In the method for producing a Si alloy-based composite material in which a Si alloy made of at least one metal selected from the group consisting of 1, Mg, Ni, Ti, Zr, Fe, Cr and Sn is infiltrated, It is achieved by a method for producing a Si alloy-based composite material, wherein the amount of C is less than 1% by mass based on SiC.

An object of the present invention is to place the above-mentioned compact and Si alloy in a furnace and heat at a vacuum degree of 5 Torr or less and at a temperature of 600 to 2000 ° C.
This is achieved by a method of manufacturing an i-alloy matrix composite material.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, Si and Al, Mg, Ni, Ti, Zr, and F are used as metals to be infiltrated into a compact.
It has been proposed to use a Si alloy made of at least one metal selected from the group consisting of e, Cr and Sn. This has a drawback that it is difficult to perform fine processing because Si, which is a conventional constituent material, is a brittle material, but brittleness can be improved by alloying this with the above-mentioned metal. Is. Here, it is particularly preferable to use an alloy of Si and Al in terms of ease of production and various physical properties.

Further, in the present invention, the amount of C in the compact is SiC.
To less than 1% by mass. Here, the reason for adding C to the compact is that the surface of SiC is usually covered with SiO ₂ , which impedes the wettability with the molten Si alloy and impedes the penetration of the molten alloy into the compact. However, this is because the addition of C to SiO ₂ has the action of reducing and removing it in the heating process. However, if the amount of C in the compact is 1 mass% or more with respect to SiC,
As described above, brittle carbides are formed and the resulting composite material becomes brittle, which is not preferable. That is, commercially available Si
In order to reduce and remove SiO ₂ formed on the surface of C powder, the amount of C in the compact is less than 1% by mass relative to SiC.
It is preferably the amount. Here, the addition amount of C is more preferably 0.1 to 0.6% by mass with respect to the SiC powder, but if less than 0.1% by mass, Si is added.
O ₂ cannot be reduced and removed during the heating process.

In the present invention, it is preferable to raise the temperature in a vacuum in order to accelerate the removal of SiO _2. The degree of vacuum is 5 Torr or less, particularly preferably 3 Torr or less. Moreover, it is preferable to heat at a temperature of 600 to 2000 ° C. The reason is that if the heating temperature is lower than 600 ° C., the penetration of the Si alloy becomes insufficient, and if the heating temperature is higher than 2000 ° C., the amount of evaporated metal increases, which is not preferable.

Further, in the present invention, Si powder may be added to the molded body in order to promote the penetration of the Si alloy,
This method is also included in the present invention. In this case, the amount of Si powder added is preferably 2 to 80% by mass of the weight of the compact, and instead of adding C to the compact, B ₄ C, T
Of course, metal carbides such as iC, VC, CrC may be added.

The present invention will be described in detail below with reference to specific examples and comparative examples of the present invention.

[Example] SiC powder (manufactured by Shinano Denki Smelting,
0.6 parts by weight of C powder to 100 parts by weight of particle size (60 μm) (S
0.6% by mass relative to iC) was added, mixed and molded to prepare a molded body. This compact and Si-Al alloy (Si / A
and a mass ratio of 40/60) were placed in a furnace and heated at a vacuum degree of 3 Torr and a temperature of 1600 ° C. to infiltrate the Si alloy to produce a Si alloy-based composite material. The composition of this material is X
Al ₄ C ₃ was not found when examined by line diffraction. The resulting composite material is machined to a width of 0.5 mm and a length of 1.
When three 00 mm grooves were formed, defects such as chipping of edges did not occur.

[Comparative Example] A composite material was prepared in the same manner as in Example except that the amount of C powder added was 2.0 parts by weight (2% by mass relative to SiC). When the composition of this material was examined by X-ray diffraction, Al ₄ C ₃ was found. When the obtained composite material was machined in the same manner as in Example, a chip was formed on the edge.

[0015]

As described above, according to the present invention,
The brittleness of the composite material of SiC and Si can be improved without generating brittle carbides, and it has the effect of facilitating the production of precision parts that require fine processing.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshifumi Takei             2-4-2 Daisaku Sakura City, Chiba Prefecture Pacific Semé             Central Research Institute (72) Inventor Tatsuya Shiogai             2-4-2 Daisaku Sakura City, Chiba Prefecture Pacific Semé             Central Research Institute (72) Inventor Mutsuo Hayashi             3-7 Makudori, Izumi-ku, Sendai City, Miyagi Prefecture             Sendai Factory Co., Ltd. F-term (reference) 4K020 AA08 AC07 BC02

Claims (2)

[Claims] 1. A molded body molded using SiC and C,
In the method for producing a Si alloy-based composite material, wherein Si and a Si alloy composed of at least one metal selected from the group consisting of Al, Mg, Ni, Ti, Zr, Fe, Cr and Sn are infiltrated, the molded body A method for producing a Si alloy-based composite material, wherein the amount of C therein is less than 1 mass% with respect to SiC. 2. The above-mentioned molded body and a Si alloy are placed in a furnace, the degree of vacuum is 5 Torr or less, and the temperature is 600 to 2000.
The method for producing a Si alloy-based composite material according to claim 1, wherein heating is performed at ℃.